Climate change associated with local extinction in peripheral populations of the threatened Italian endemic plant Santolina etrusca (Asteraceae)

Summary The role of climate change as a driver of local extinctions has rarely been tested using primary distribution data, largely due to the scarcity of such data for many species, especially from historical periods. Santolina etrusca (Asteraceae), an Italian endemic shrub listed as Near Threatened on the International Union for Conservation of Nature (IUCN) Global Red List of Threatened Species, is a notable exception, as both historical and current distributional data are available for it. In this study, we documented the distribution changes of this species, highlighting the local extinction of populations located in the northernmost and southernmost edges of its historical range during the twentieth century. Direct anthropogenic impacts on land use are unlikely to have been the primary causes of local extinctions, although the absence of historical data prevents us from ruling out past anthropogenic drivers. By analysing the ecological conditions at sites hosting extinct versus extant populations, we identified significant climatic factors that are potentially responsible for this range contraction. Our findings provide empirical evidence of an association between climate change and local extinctions in a Mediterranean plant, suggesting that greater temperature seasonality, continentality and annual temperature range are linked to range contraction.